[RKOTLIN-877] Avoid exporting Core's symbols to allow mixing multiple SDKs

.github/workflows/pr.yml

@@ -144,6 +144,7 @@ jobs:
             -DREALM_ENABLE_SYNC=1 \
             -DREALM_NO_TESTS=1 \
             -DREALM_BUILD_LIB_ONLY=true \
+            -DCMAKE_CXX_VISIBILITY_PRESET=hidden \
             ../../src/jvm
             make -j8
 
@@ -213,6 +214,7 @@ jobs:
           -DCMAKE_BUILD_TYPE=Release `
           -DREALM_ENABLE_SYNC=ON `
           -DREALM_NO_TESTS=1 `
+          -DCMAKE_CXX_VISIBILITY_PRESET=hidden `
           -DVCPKG_TARGET_TRIPLET=x64-windows-static
           cmake --build . --config Release
 

CHANGELOG.md

@@ -4,6 +4,7 @@
 - None.
 
 ### Enhancements
+- Avoid exporting Core's symbols so we can statically build the Kotlin SDK with other SDKs like Swift in the same project. (Issue [JIRA](https://jira.mongodb.org/browse/RKOTLIN-877)).
 - Improved mechanism for unpacking of JVM native libs suitable for local development. (Issue [#1715](https://github.com/realm/realm-kotlin/issues/1715) [JIRA](https://jira.mongodb.org/browse/RKOTLIN-1065)).
 
 ### Fixed

packages/cinterop/build.gradle.kts

@@ -494,6 +494,10 @@ fun getSharedCMakeFlags(buildType: BuildType, ccache: Boolean = true): Array<Str
         add("-DREALM_NO_TESTS=1")
         add("-DREALM_BUILD_LIB_ONLY=true")
         add("-DREALM_CORE_SUBMODULE_BUILD=true")
+        // This will prevent exporting Core's symbols which is useful when combining for example the Swift SDK and Kotlin Multiplatform
+        // in the same app. The generated dynamically linked shared Framework from Kotlin/Native can then be linked dynamically into the iOS app (!use_frameworks in Cocoapods)
+        // or statically. This will also reduce the binary size a little bit (avoid storing metadata about exported symbols)
+        add("-DCMAKE_CXX_VISIBILITY_PRESET=hidden")
     }
     return args.toTypedArray()
 }